A root canal treatment may be used to preserve a tooth that has or could develop a diseased pulp cavity. To prevent bacterial proliferation within the root or pulp canal of the tooth, the canal is enlarged without excessively weakening the root's wall in order to: 1) mechanically remove as much of the root canal contents as is possible and 2) allow the introduction of irrigants into the root canal space that dissolve and disinfect organic debris, thus minimizing the presence of bacteria, as well as clearing the walls of the root canal of calcific debris created during instrumentation. After completing steps 1 and 2, the root canal is typically filled or obturated with a material such as gutta-percha and a sealer to occlude the pulp cavity and thus seal the root canal.
Irrigation assists in removing debris and necrotic material remaining after the endodontic files, bores, and reamers used during the removing and shaping steps of the procedure. Although the irrigant preferably is capable of dissolving or disrupting soft tissue remnants to permit their removal, the irrigant may be any suitable liquid such as water or various alcohols. More particularly, although some degree of debridement is preferred, any fluid may be used to flush debris from the root canal. General examples of appropriate irrigants include hydrogen peroxide and sodium hypochlorite.
In essence, the procedure goal is to convert the root into a devitalized tissue autograft. As such, it is important that the root canal is properly cleared of all debris before being filled. However, it is nearly impossible to visually determine if a root canal on a tooth, or analogous tiny channels, have been fully cleaned and flushed. Further, due to the small diameter of the canal (e.g., about 0.25 mm) and the curved geometry, it cannot be easily imaged using current technology. In addition, roots have complex morphology including accessory canals. As a result, current techniques involve relying on the experience and skills of the practitioner cleaning the canals to help assure a clean canal for an effective procedure. Failing to remove all of the necrotic tissue and bacteria often causes the procedure to fail, at which point the patient must have the procedure redone or have the tooth extracted. Thus, providing an improved method of determining whether the root canal is clean before obturation will improve the efficacy of the root canal treatment.